Why do so many web development companies websites fail W3C validation?

[ro0bear]

empty alt attributes on images and sometimes none...etc. etc.

I just thought it might be worth mentioning something here that I learnt a little while ago. In regards to screen readers an image without an alt attribute is bad, because a screen reader will read out the file name instead, however an image with an empty alt attribute is good if the picture is merely for decoration and has no significance other than a cosmetic one, because a screen reader will ignore an empty alt attribute.

ro0bear

[Aleksejs]

In my experience the fact that developers site does not validate properly or the fact that site that they have made for clients (but this is tricky, because client themselves could have altered code) fails validation is very prominent sign that shows the lack of programming standards, testing procedures. All the invisible procedures that are required for web application to be designed secure.
After all, it is much easier to do extrusion detection if you have strict guidelines on how output should look like (and these guidelines, if they exist at all, almost always are more strict than HTML/XHTML specification).

[ro0bear]

(but this is tricky, because client themselves could have altered code)

In my opinion a client should not be given the ability to alter code. The CMS should be set up in a way to make it impossible for the client to have anything to do with the code, only the content. In the same way somoeone shouldnt drive a bus if they dont have a licence and know nothing about buses, a client who knows nothing about code, coding standards, and coding structure shoudnt have anything to do with code.

[Aleksejs]

roObear, never underestimate the willingness to tinker with something you are not allowed to tinker with
Immagine, for instance, that CMS did not allow client to embed google map in their website, so instead of going to the original developers to request that feature - they decide that they embed it themselves... with the help of FrontPage

[cyjetsu]

I believe that generally clients don't know about validation so web designers who should know better can get away with uploading crappy code for professional business sites.

[risoknop]

Dreamweaver

And there, imho, lies the problem. Do not use Dreamweaver unless you are capable of coding accessible and standards compliant Web site by hand.

No matter how you configure Dreamweaver it will output crap (and I am not exaggerating). You might try very hard and get it to output compliant code, however it will still output incredibly bloated and unsemantic markup.

By coding manually (that doesn't mean typing in Notepad, just for clarification, you can use any advanced editor, even Dreamweaver, just don't use the WYSIWYG), your markup will be much smaller (I have seen cases where hand coded markup was 10 times smaller than the same functionality Dreamweaver output... which is a huge difference) and semantic (Dreamweaver doesn't understand what "semantic" means and it uses, most of the time, inappropriate tags, even though they migh validate the result wll be inaccessible Web site).

If you need a WYSIWYG editor to design a Web site, you should get out of Web design business now... Just my two cents.

[ro0bear]

I have seen cases where hand coded markup was 10 times smaller than the same functionality Dreamweaver output.

[risoknop]

This is mainly problem with stylesheets. It is very common Dreamweaver outputs some 20KB bloated stylesheet and then when I code the styles by hand, I find out that more than a half of the Dreamweaver stylesheet is not needed...

Moreover, my hand-written styles are more cross-browser compatible and better structured

[logothon]

This is mainly problem with stylesheets. It is very common Dreamweaver outputs some 20KB bloated stylesheet and then when I code the styles by hand, I find out that more than a half of the Dreamweaver stylesheet is not needed...

Moreover, my hand-written styles are more cross-browser compatible and better structured

i totally agree. i use Dreamweaver, but code everything by hand and use split view so i can see how it looks. but the thing with Dreamweaver is that it doesn't use any shorthand declarations by default. ex. margin: 10px 0 10px 0; you have to go into the prefrences and change it to write shorthand (at least with MX 2004). and if your using WYSIWYG for the CSS that adds up real quick. and if your using WYSIWYG, chances are your not changing your prefrences.